I am a duel US-HK citizenship and I love it! It makes travel much easier, not to mention it opens up a lot of career and investment opportunities. I was born in HK and emigrated to the US when I was an infant.
Some countries forbid duel citizenship. This article reveals which do and don't allow it:
http://en.wikipedia.org/wiki/Dual_citizenship . In Canada, they were considering passing a law to forbid dual citizneship. I doubt it will pass though. But even if it does, you can always surrender your HK residency and reclaim it later on. I believe once you've established right of abode in HK, you can never lose it unless you formally renounce it to the HK government.
